1. Field of the Invention
The present invention relates to a manufacturing method of a semiconductor device, a liquid crystal display device and an EL display device using a droplet discharge method typified by ink jet printing. In particular, the invention relates to a forming method of a contact hole provided in the semiconductor device.
2. Description of the Related Art
In the manufacture of semiconductor devices, liquid crystal display devices or EL display devices, it has been suggested that a droplet discharge apparatus is used to form thin films and wiring patterns in order to reduce the equipment cost and simplify the steps.
In such a case, a contact hole of a semiconductor device is formed by the steps of prebaking a resist applied on an entire surface of a substrate, forming a resist pattern by photolithography in which UV rays and the like are irradiated through a mask and developed, and etching and removing an insulating film, a semiconductor film, a metal film and the like that are to be a contact hole using the resist pattern as a mask.
Patterning can be performed relatively easily by an exposure apparatus in the case of a glass substrate or a display panel being small. When the size of a substrate increases, however, an entire surface of a display panel cannot be processed at a time by one exposure step. Accordingly, an area on which a photo resist is applied is divided into a plurality of blocks and an exposure step is sequentially performed for each predetermined block, thereby an entire surface of a substrate is exposed (for example, see Patent Document 1).
[Patent Document 1] Japanese Patent Laid-Open No. 11-326951
However, in the case of forming a contact hole by a conventional manufacturing step of a semiconductor device, a resist is required to be formed on almost entire surface of a substrate so as to be applied on a film other than an area in which a contact hole is formed, leading to drastically reduced throughput. Even when throughput is improved, in the case where the amount of the resist being applied and the surface quality of a base film are not sufficiently controlled, the contact hole is also covered with the resist and contact defects may occur.